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Originally shared by 3D Hubs
Tangled Filament, could headphones teach us how to solve this problem? #3dprinting
‘Could filament be extruded flat rather than rounded? and also would it be possible to adatp the nozzle to a new form factor?’
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Flat wired earphones don’t tangle as much as round wired ones…
@Sanket_Shah true that
Is filament tangling really enough of a problem to justify another shape of filament? Except for a loose, unspooled bundle, I haven’t had a filament tangle in quite some time. I think it’s just going to make hot end and extruder design more of a pain for very little gain.
Yeah, it happens at most twice before you realize you need to be diligent… Round filament is easy to produce, will heat uniformly, cheap, exists already… I don’t see too many con’s with current filament…
Besides, I make my own hot-ends and if you gave me some rectangular stuff to work with I’d just pass it back to u and say “find me a drill that shape”…
Hot-ends would cost too much to produce…
Continue the discussion but, I’ll stay with round!
I think Stratasys has a patent on flat filament. While drilling rectangular holes isn’t so easy you can sure get a better grip on the flat side for driving. Also easier to melt evenly as filament size grows plus less tangling as the post indicates.
The Stratasys Genesys machines used wafers back in the mid 90s.
I think the hot ends melt chambers could be drilled then milled. I just question the need for making a new filament form factor now. With a little bit of care, you can get filament to drive nicely without tangles or jams for many months on end, or with a lot of hassle, you can redesign hot ends, cold end feeders, new filament extruder dies, new resizing dies, throw inventory issues into the mix for filament suppliers and so on. It also probably throws a monkey wrench in Bowden designs.
On the other hand, flat wires/filaments still do tangle sometimes, and they’re subject to kinds of damage that round ones aren’t. The only flat-feeder designs I’ve thought were worthwhile were the kind that used existing uniform-thickness stock cut into flat strips, e.g. from bottles. But those never went very far.
I had this idea and did some sketches after seeing the video of a guy making a simple tool to convert a 2 liter bottle to rope and lashing. Since it was PET, it would make nice filament for pennies. The drive gear would be easy enough with an idler bearing. The cold and hot zone could be a two part affair with one side milled out making a square pocketable the cap being milled flat. A cartridge heater would do. There could be a transition to a barrel shape and a typical tip like we use on the standard Ubis hotend. All totally doable.
Talk about recycling!
Brook
I wonder if you could mill a transitional cavity shape that would fold the flat strip into something more compact as it neared the heat.
@paul_wallich Kind of. My thoughts would be a slot that tapers to a cone as it gets closer to the nozzle, diagonal mill passes would do just that. I don’t think there should be enough room for “folding”, I’m pretty sure that would complicate things, particularly the ability to provide pressure, and the ability to remove the material.
Plus the point is that its faster to heat as a flat piece. The transition to circular (or if you’re really slick you retain a non unity aspect ratio and spin to change line thickness) happens after melting.
I think we may be talking past each other. I’m thinking about maintaining the 2D aspect ratio until the melt point, but going from a flat slot to a folded one (think “V” for the simplest version) as you get to the melt zone. I think (perhaps wrongly) that if you transition entirely after melting you’re going to have a lot of material toward the edges that doesn’t flow. (And same for a slotted extruder unless you’re way more sophisticated with pressure than most 3D printers.)
I think I just misinterpreted what you meant by “folded”. Sounds like maybe we’re talking about the same thing.
As soon as it hits the hot zone, it would be molten so shape doesn’t matter much. It would end up as a cylinder once molten. I think this would work.
Yes any cold filament on top of the melt zone acts as a plunger and will push the molten stuff out no matter what the shape (within reason)
I think if you consider a nozzle with a rectangular slot which tapers down conically into a hole at the tip, you would be paying minimum 3x more for nozzles… There would be no competition from backyarders or small setups making nozzles, it would only be possible to do economically on a CNC and even then would take a lot longer to make than a standard nozzle…
I’ve had a little time to think about it, I don’t believe it would be all that much more expensive to do a slotted heater block. Minimizing the heat break cross section is something I haven’t figured out. It seems a ribbon filament system would increase thermal losses for metal barrel systems.
This is the video that got me thinking about a hotend for flat filament made from plastic bottles.
Step one: someone design a 3d printed part to do this. Why not 1.75mm width?
Step two: design a hotend to accept it. I’ll be happy to mill a design on my tormach
Step three stop buying filament and print with recycled bottles.
Brook